Abrasive throwing machine



.lune 18, 1940.A

` l D. c. TURNBULL a ABRASIVE THROWING MACHINE Filed Feb. 5, 1934 2 sheets-sheet '1 ATTO R N EYS Patented June 1 8, 1940 PATENT OFFICE N 2,204,632 liusmislvr: 'rnnowlNc MACHINE David C. TurnbulhMishawaka, Ind., assigner to The American Foundry Equipment Company, Mishawaka, Ind., a corporation of Delaware Application February 5, 1934, Serial- No. 709,727

. 16 Claims. This invention relates to abrasive throwing machines and more particularly to a centrifugal abrading machine for throwing a stream of abrasive at a blasting velocity so as to electively 5 clean metal sheets, castings and the like.

Accordingto this invention the machine is designed and constructed so as to protect the machine interior from the wearing effects of the abrasive as it moves through the machine, all wear from this cause being substantially conlined tolcertain removable and replaceable abra-l sive propelling blades, formed of wear resisting metal, which can be quickly and easily removed and replaced when necessary.

The machine generally comprises a rotatably mounted disc having an annular surface den sive fed into the machine is directed and an enclosing side wall having spaced abrasive discharge openings or outlets through which the abrasive escapes. A plurality of throwing blades are radially arranged in spaced relationship around the disc and extend from the`feed chamber to the periphery of the disc. The throwing blades are so arranged as to deiine therebetween a passage through which the abrasive discharge from the openings in the distributor cage Knows, the blades providing removable wear surfaces along which the abrasive moves prior to-vits discharge from the machine. The inner end of each blade is positioned against or adjacent to the feed chamber with the discharge aperture therein positioned slightly in advance of the blade. Each abrasive discharge opening and abrasive passage provides an outlet for the abrasive supplied to the feed chamber` The discharge openings are shaped and arranged to conduct all of the abrasive directly into the passage and out of abrading contact with the disc or other perinanent parts of the machine.

The discharge end of the feed pipe is pref- 46 erably held in an off-center position with rspeci; to the converging bottom wall of the charnber, and is so arranged that the abrasive flowing from the discharge end of the feed pipe strikes the bottom Wall of the rotating chamber and is 5U then thrown peripherally therefrom through the discharge openings in the side walls of the cham-A 515 described, is discharged at a predetermined point over an area approximately one-fourth of the disc periphery. Discharge from the machine begins at approximately 180 from the point where the abrasive is fed into the feed chamber and the discharge continues for approximately 90 5 from the point of initial discharge.

An object of this invention is to provide an abrasive throwing machine which is so constructed that the machine interior is protected from the wearing effects of the abrasive moving through the machine. Y

Another object of this invention is to provide an abrasive throwing machine adapted to throw abrasive at blasting velocities, the machine hav` ing associated therewith means for controlling. m5

the delivery of the abrasive so that substantially al1 wear caused by the moving abrasive -is'conlined to removable and replaceable wear blades which are inexpensive to make and easy to remove and replace. 20

Another object of this invention is to provide an abrasive throwing machine which is simple in construction, economical to manufacture, which has a low power consumption for the work done, which imparts to the abrasive particles a highly effective abrasive velocity, which causes a minimum disintegration of the abrasive particles, which is durable and lasting in construction, which is not subjected to excessive wear by the abrasive passing through the machine from 30 which the thrown abrasive may be directionally controlled4 and which is highly adaptable for the cleaning of metal sheets, forgings, metal parts andv other articles.

Other`objects of this invention will become 35 apparent as the disclosure proceeds.

In order that a clearer understanding of my invention may be had, attention is hereby directed to the accompanying drawings, forming part of this application and illustrating certain 40 possible embodiments of my invention.

Referring to the drawings:

Fig. 1 isa face view of the abrasive machine with certain parts broken awayto lmore clearly i illustrate the construction;

Fig. 2 is a side view of the `abrasive machine;

Fig. 3 is a transverse cross sectional view through the machine, this view` being taken on line 3--3 of Fig.` 1; v

Fig. 4 'is `a cross sectional view through the 50 feed chamber associated with the machine, Ithis view being taken in line 4 4 of Fig. 3;

Fig. `5 is a perspective view of theremovable abrasive throwing blade associated with the machine; v

Fig. 6 is a diagrammatic view illustrating the direction of movement of the abrasive thrown from the machine when the abrasive is fed into the machine at a designated point; and

Fig. 7 is an enlarged vertical cross sec-tional view through a feed chamber of somewhat modied construction.

According to this invention abrasive particles such as sand, steel, grit or shot are fed into a feed chamber centrally mounted within a rotor. The rotor may comprise spaced discs I and I joined together by radially arranged members spaced apart to define passages therebetween through which'abrasive is discharged. The rotor is mounted upon a rotatable shaft 5 having a hub 6 connected thereto by means of a spline 40. The hub t is removably connected to the disc i` of the rotor by means of the bolts l.

'Ihe feed chamber c resembles a pot in general shape. The chamber c may be provided with feet 24 projecting from the bottom or` rear wall thereof which rest against the inside face of the disc I. The pot is positioned within the rotor through a central openingprovided in the disc l5. The feed chamber is provided with a laterally projecting rim around the mouth thereof which fits within the opening provided in the disc member l5. A ring member 26, which overlaps the rim 25 and is secured to the disc I5 by means of the bolts 2l, retains the feed chamber in position within the rotor. A stud '39, extending inwardly from the ring member 26, projects through a cutout opening 45 in the rim 25 of the eed chamber, holding the feed chamber firmly locked Within the rotor so as to rotate therewith.

The abrasive is supplied to the feed chamber through the feed pipe f. The discharge end 65 of the feed pipe f is positioned slightly off-center so that the abrasive discharged from the feed pipe strikes the conical shaped bottom 20 of the feed chamber at one side of the cone point 46.` The side wall of the feed chamber comprises side wall portion 2| which extends substantially parallel to the axis of rotation ofthe rotor and a contracted side wall portionv 22 which joins the side wall portion 2l to the rim 25. The side wall portion 2l is provided 4with openings 23 through which abrasive, fed into the feed chamber, is discharged.

'Ihe discs I and I5 may be joined by webs each comprising an ,advancing vane 2 and a following vane 3 having an apex portion 4 joining the varies 2 and 3.

One or more propelling blades b, shown more particularly in Fig. 5, made of heavy wear resisting material, are mounted within therotor to provide one or more abrasive passages. The blade blies between the discs I and I5 and extends from the feed chamber c to the outer periphery of the rotor. One abrasive discharge opening 23 is preferably provided for each abrasive propelling I I and I2 which protect the discs I and I5 respectively from Vcontact with the flying abrasive. 'I'he blade bvmay be removably secured within the rotor by any convenient means. For purpose IofA illustration, the disc member I may be, properiphery of the rotor.

vided with a projecting shoulder I6 adapted to seat within a groove I3 cut in the side wall II of the blade b. A set screw I4 extends through the disc member I5 which may be screwed into abutment against the side wall portion Il of the blade to lock the blade in position. Other well known means for removably securing the blade in position, however, may be used. The inner ends I'I of the side wall portions II and I2 of the blade may also `be flared outwardly if desired to more readily catch the abrasive emitted from the discharge openings 23.

As shown more particularly in Figs. 2 and 3, the discs I and I5 may be provided with heavy rim portions I8 which balance the rotor and steady the rotative movement thereof. The rim portions Il may be cut away as at I9 to provide guideways into which the side edges of the blade b extend, as shown more particularly in Fig. 2. It will be evident by referring to Figs. 1, 2 and 3 that the blades b may be withdrawn outwardly of the rotor through the guideways upon manipulation of the set screw I4, which as shown in Figs. l and 3 is provided with a tool-engaging recess Ida.

There is shown in Fig. 7 a feed chamber of somewhat modified construction. The modified feed chamber as shown may be made from assembled parts comprising a bottom or rear Wall member having welded thereto a sheet metal side Wall forming member 3l. A collar member 32 providing a contracted opening or mouth for the feed chamber is welded or otherwise secured to the other end of the side wall 3 I. The side wall memberBI may be provided with an outwardly flared rim portion 33 and provides a convenient means for securing the feed chamber or container in place within* the rotor. Spaced abrasive discharge openings 34 are provided in the side wall 3I through which the abrasive is ejected from the feed chamber.

I The abrasive discharge openings 23, as shown in Figs. 2 and 3, are of less width than the distance between the spaced discsy I and I5 and are otherwise soshaped and arranged that the abrasive when discharged is conducted directly on to the propelling blade b and is given no opportunity to contact the sides of discs I and I5 so as to appreciably wear the same. 'I'his is an important feature of this invention, whereby the abrasive during its movement through the machine at abrasive velocities contacts the replaceable blades only and is substantially kept out of abrasive contact `with other parts of the machine.

When abrasive is fed into the feed chamker atapproximately the point f', asshown in Fig. 6, the abrasive a will be thrown bythe machine approximately as shown. Discharge begins at a point approximately 180 in advance of the point of entrance of the abrasive into the machine and continues for f approximately 90 around the The major portion of the abrasive is thrown from the right hand side of the center line of the wheel soas to effectively clean metal articles placed upon `a suitable work support positioned below the wheel. A wheel having a diameter of approximately 19 inches will clean a path from 3 to 4 feet in length when the rotor is driven at 2250 revolutions per minute. There is little wear on the moving parts of the machine except only that wear to which the advancing v'faces of the blades b are subjected. 'I'he blades, however, can be inexpensively made and can be easily and quickly replaced when worn.

The direction in which the abrasive is thrown may be regulated by adjusting the position of the discharge end of the feed pipe f with respect to the rotating axis ofv the machine, The feed chamber operates to depositvthe abrasive onto the advancing faces of the blades.

The machine is adapted for a variety of different uses, such as the cleaning of metal sheets, castings and other articles. The machine may be mounted upon any suitable standard or may be associated with other apparatus, such as a tum'- bling mill. 'I'he machine is made of few parts, and may be inexpensively manufactured and assembled. It is furthermore, strong and durable in construction, safe and substantially foolproof` in operation, requires little oor space,- and is highly efficient.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. A machine for throwing abrasive at blasting velocities including in combination, a rotatable abrasive feed chamber including a containing wall, and a throwing blade radiating outwardly from said wall, said containing wall having an opening therein of limited axial and circumferential dimensions adapted to conduct the abrasive deposited in the chamber on to said blade, said opening being positioned in advance of said blade.

2. A centrifugal 'abrading machine operative to throw abrasive at blasting velocitiesincluding in combination, a rotatably 'mounted disc. a feed chamber comprising an enclosing Wall centrally mounted to rotate with said disc, and an abrasive propelling blade mounted on said disc and radially arranged with respect to said chamber, said enclosing wall having a discharge outlet therein through which the abrasive is conducted from the chamber onto the inner end of said blade, and means for supplying abrasive to said chamber.

3. A machine for throwing abrasive including in combination, a rotatably mounted feed'chamber comprising a tubular member having a plurality of abrasive discharge openings therein, a rotatably mounted throwing blade -associated with each of said openings arranged around said member operative to throw the abrasive emitted from the opening, each of said openings being positioned slightly in advance of its associated blade.

4. A machine for throwing abrasive at blasting velocities including in combination, a rotatably mounted feeding chamber having a surrounding side wall, rotatably mounted propelling blades arranged around the side wall of said chamber, said chamber having a discharge opening in the side wall thereof adjacent to the inner end of each blade, and means for depositing abrasive in said chamber.

5. A machine for throwing abrasive at blasting velocities including in combination, a rotatably mounted member adapted to be rotated at high speed, afeed chamber centrally mounted on said member, said chamber having a cone shaped rbottom wall against which the abrasive is directed and a surrounding side wall having spaced discharge openings therein, and throw'ing blades arranged around said chamber; Y

6. A machine for throwing abrasive at blasting velocities "including in combination, a rotatably mounted disc, a feed chamber centrally mounted on said disc, said chamber comprising a converging bottom wall against which the abrasive is directed and a surrounding side wall having spaced discharge openings therein, throwing blades arranged around said chamber and extending from the chamber to the disc periphery, and means for depositing abrasive off-center into said chamber.

7. A machine for throwing abrasive comprising spaced rotatably mounted discs, a tubular member fixed to rotate with said discs, abrasive throwing blades arranged around said member and removably positioned between said discs, and openings in said `tubular member operative to deposit abrasive in the path of rotation of said blades.

8. A machine for throwing abrasive including in combination, a rotor comprising spaced discs, a rotatable abrasive feed chamber comprising a tubular member centrally positioned between said discs'having a plurality of discharge openings therein, a throwing blade associated with each of said openings arranged around said member operative to throw the abrasive emitted from the opening, said openings being of less width than the distance between said discs and so shaped and arranged as to direct the moving v.abrasive into the path of said blades and out of wearing contact with said discs..

9. An abrasive machine for cleaning metal sheets, castings and the like which includes, a

rotatably mounted abrasive feeding chamber, means for supplying the abrasive to said chamber, removable `throwing elements arranged around said chainber and rotatable therewith, and a. `contracted discharge opening in said chamber operative to conduct the abrasive into the path of rotation of said removable elements and out of contact withthe permanent parts of the machine.

10. An abrasive throwing wheel including in combination; an abrasive container positioned centrally within said wheel, throwing blades arranged around said container, an opening in said container operative to conduct the abrasive deposited in' said container across the inner ends of said blades and into the path'of movement thereof, said container including anV enclosing side wall, the side wall portions defining a con-- tracted opening through which the abrasive is Vinjected into the container, said container and a plurality of abrasive propelling blades of chan-' nel-shaped cross-section provided thereon, said blades terminating short of the axis of rotation of said rotor to dene a central space, said rotor having in said central space afeed member comprising a'tubular side wall having an inwardly facing abrasive supporting surface rotating synchronously with said rotor, said tubular sidewall overhanging the inner ends of said blades and having a ldischarge edge adjacent the path of rotation of Ithe inner ends of said blades and be tween the paths of rotation defined by the ilanged side edges of said blades, and means for supplying abrasive to 'said side wall.

12. In an abrading apparatus, a structure mounted'for rotation at high speed and having a plurality of abrasive propelling blades provid'ed thereon, means mounted adjacent the center of rotation of said structure for feeding a stream of abrasive over the edges of said blades causing the abrasive to be picked up and discharged by said blades, said means comprising a tubular viding an inwardly facing outwardly inclined surface leading to a discharge edge disposed between the side edges of said blades, and means for depositing abrasive on said surface.

13. In an abrading apparatus, a rotor mounted for rotation at high speed and having a plurality of abrasive propelling blades supported thereon, said blades terminating short of the axis' of rotation of said rotor to deine a central space, a generally cylindrical feed member secured to said' rotor to rotate with said blades, said feed member extending into said central space, said feed member having a discharge edge located in a plane normal to the axis of rotation of said rotor and disposed between the `side edges of said abrasive propelling blades.

14. A centrifugal abrading machine including I feed chamber and -discharge onto the inner end of said blade.

15. In an abrading apparatus, a rotor mounted for rotation at high speed including a side wall member having a plurality of abrasive propelling blades supported thereon, said blades terminating short of the axis of rotation of said rotor to define a central space, a generally cylindrical feed chamber secured to said rotor to rotate with said blades, said feed chamber extending into said central space, said feed chamber having a discharge edge located adjacent the inner ends of said blades and between the side edges thereof, and means for feeding abrasive to said feed chamber.

16. In an abrading apparatus, a rotor having a plurality of abrasive-propelling blades terminating short of the axis of rotation thereof, abrasive feeding means having a tubular side wall whose axis is coincident with the axis of rotation of said blades, said side Wall being fixed to rotate synchronously with said blades providing an inwardly facing abrasive supporting surface of generally circular cross-section, said side wall having a discharge edge disposed adjacent the path of rotation of the inner ends of said blades and between the inner side edges thereof, and abrasive supply means for depositing abrasive upon said surface.

DAVID C. TURNBULL. 

